Many types of commercial and industrial systems involve processes in which liquids are supplied via fluid control systems that may include a variety of both pumping assemblies and control valves. These fluid control systems include, but are not limited to, those used in electrical power stations, chemical manufacturing operations, food and beverage processing, liquid gas supply and disposal, water supply and disposal, heating, ventilation, and air conditioning (HVAC) systems, etc. Improving the control mechanisms for the various components of these fluid control systems may reduce energy usage and increase the efficiency of these systems.
In typical conventional fluid control systems, the control valve assemblies provide a feedback signal based on the assumption that the valve's closure member position always follows the valve actuator valve stem position. Generally, there is an assumption that the valve linkage is properly set up and fully operational, even though this may not be the case. Error can be introduced into the system because there is a mechanical linkage between the traditional valve actuator and valve that can introduce an error from backlash, movement hysteresis, or malfunction. Typically, fluid control valve assemblies provide the position of the valve stem. However, if the water flow is non-linear relative to the valve stem position, the position feedback signal may not indicate the percentage of fluid flow through the valve.
Typically, flow meters are physically piped in series to measure the fluid flow volume through the valve, and are usually located externally to the valve body. These flow meters may be used in industrial and/or HVAC applications.
Embodiments of the present invention represent an advancement over the state of the art with respect to fluid control systems and the control thereof. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.